1. Technical Field
The field of art to which this invention pertains may be generally located in the class of devices relating to valves. Class 137, Fluid Handling, United States Patent Office Classification, appears to be the applicable general area of art to which the subject matter similar to this invention has been classified in the past.
2. Background Information
Present day industrial plants employ a variety of machines which are provided with fluid pressure control systems that are operated by air pressure. The fluid pressure control system for such machines vary from machine to machine. Some fluid pressure control systems employ a directional control valve provided with a pressure regulator valve, while other such systems may employ a pressure regulator valve and a flow control valve means with a directional control valve, and still other systems may employ only a flow control valve means with a directional control valve. Heretofore, if a directional control air valve was required in a fluid pressure control system which was to be provided with a pressure regulator valve or a flow control valve means it was necessary to provide a sandwich or interface plate that would be mounted on the directional control valve manifold or base, and the pressure regulator valve and the flow control valve means would be mounted on the sandwich or interface plate. The problem created by the use of sandwich or interface plates, for adding a pressure regulator valve or a flow control valve means to a directional control valve structure, is that such additions enlarge the overall directional control valve structure, increase the cost and weight of the valve structure, and make such structure more complex. The enlargement of a directional control valve structure by the use of such sandwich or interface plates, when employed on a stacking directional control valve, is a disadvantage, because in many instances the directional control valve structure must be mounted in a very small space or area on a machine that it is controlling, as for example, a robotic device. A further disadvantage of the use of sandwich or interface plates for adding a pressure regulator valve or a flow control valve means is that such plates add additional weight to the overall valve structure, which is a disadvantage when the valve must be employed on a robot arm which is moved between many operative positions. A typical example of a prior art directional control valve, which employs sandwich or interface plates for the provision of a pressure regulating function and a flow control function is described and illustrated in the U.S. Pat. No. 3,513,876 to Tarbox.
It is a primary object of the present invention, to provide a novel manifold stacking base which overcomes the problems of increased cost, increased weight and enlarged structures, when it is required to provide pressure regulating and flow control functions with the use of a sandwich plate in a pneumatic control system. It is another object of the present invention to provide a novel manifold stacking base which is light in weight, compact in structure, and which is adapted to selectively provide either both pressure regulating and flow control functions, or neither of said functions. It is a further object of the present invention to further provide a novel manifold stacking base for a directional control valve structure which does not require a sandwich or interface plate in order to provide any required pressure regulating or flow control functions. It is still another object of the present invention, to provide a novel manifold stacking base for a directional control valve structure which provides a low profile valve structure, yet which can be employed to provide pressure regulating and flow control functions.